High Production Rate Process of YBCO Coated Conductors by TFA-MOD Process

Influence of process conditions including water vapor partial pressure, gas flow rate and total annealing pressure on YBa2Cu3O7-y (YBCO) film growth has been investigated in order to clarify the YBCO growth mechanism and to increase the growth rate. YBCO films have been fabricated on a LaAlO3 substrate by metalorganic deposition (MOD) process using tri- fluoroacetates (TFA) as a solute source. It was found that the processing parameters such as high water partial pressure, high diffusion constants due to low total pressure, and high gas flow rate affect the YBCO growth rate. Furthermore, it was empirically suggested that the growth rate of the YBCO film was in proportion to both the square root of water partial pressure and gas flow rate and was in inverse proportion to the one sixth power of the total pressure. The YBCO growth rate of about 2 times as fast as the previous condition was achieved with high performance by optimizing the process parameters.

[1]  Y. Shiohara,et al.  Highlights of coated conductor development in Japan , 2006 .

[2]  T. Saitoh,et al.  Advanced TFA-MOD process of high critical current YBCO films for coated conductors , 2004 .

[3]  Y. Shiohara,et al.  Fabrication of YBCO film by TFA-MOD process at low-pressure atmosphere , 2004 .

[4]  Y. Shiohara,et al.  Growth mechanism of YBCO films in metal organic deposition method using trifluoroacetates , 2003 .

[5]  Y. Ikuhara,et al.  Growth mechanism of Y123 film by MOD-TFA process , 2002 .

[6]  Y. Ikuhara,et al.  Crystallization mechanism of Nd_1+xBa_2−xCu_3O_7−y and YBa_2Cu_3O_7−y films deposited by metalorganic deposition method using trifluoroacetates , 2002 .

[7]  Dominic F. Lee,et al.  Low cost Y-Ba-Cu-O coated conductors , 2001 .

[8]  Dominic F. Lee,et al.  Fabrication of long lengths of YBCO coated conductors using a continuous reel-to-reel dip-coating unit , 2001 .

[9]  D. L. Overmyer,et al.  Thick sol-gel derived YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// films , 2001 .

[10]  D. L. Overmyer,et al.  Thick Sol-Gel Derived YBa{sub 2}Cu{sub 3}O{sub 7-x} Films , 2000 .

[11]  H. Wiesmann,et al.  Kinetics of YBa2Cu3O7 film growth by postdeposition processing , 2000 .

[12]  M. Cima,et al.  High critical current density thick MOD-derived YBCO films , 1999, IEEE Transactions on Applied Superconductivity.

[13]  John A. Smith,et al.  Effect of growth conditions on the properties and morphology of chemically derived epitaxial thin films of Ba2YCu3O7−x on (001) LaAlO3 , 1992 .